Automatic reversible electric switch



Dm. 3, 1935. @,LKESSLER 2,023,139

AUTOMATIC REVERSIBLE ELECTRIC SWITCH Filed Feb. 24, 1954 1 2Sheets-Sheet l 3 Fiyi] INVENTOR.

z'a Kass [er Mm Mm. Y A TTORNEYS.

Mmm, 3, E. o. KESSLER I 2,023,139

AUTOMATIC REVERSIBLE ELECTRIC SWITCH Filed Feb. 24, 1934 2 Sheets-Sheet2 "5 j "l, f2/49 4a4 35 l 6h33 /39 39 -w31 a; 7 `/ZZ if v INVENTOR.

oKess/er 32%@ i?, WM

A TTORNE YS.

Patented Dec. 3, 1935 UNITED STATES PATENT OFFICE :guardata AUTOMATICREvERsIELE ELECTRIC SWITC This invention relates to automaticreversible' -lectric switches adapted for use in connection with varioustypes of rotary machines, such as rotary electric furnaces, laundry tubsand the like, wherein the carrying member or container f such machinesmay be rotated or rocked backwardf'and Aforward variable distances, in away to agitate or keep in motion the contents of the container.

The purpose of my invention is to provide a switch that may beoperatively connected to a rotatable electric furnace, laundry tub, orthe like, and which in turn will serve to cut out and turn on thecurrent to the motor operating the furnace, and so that the furnace willbe automatically reversed at pre-determined times in its rotarymovements.

It is also an object of the invention to provide means whereby theamount of rock or throw of the cylindrical furnace may be increased ordecreased from time to time, as is usually desirable, as for instance itis customary to start such furnaces by imparting thereto comparativelyshort rocking movements and to increase their distance of travel fromtime to time over a period of perhaps fifteen or twenty minutes, theapproximate time ordinarily required to melt a charge of brass.

The invention is fully disclosed in an accompanying embodiment thereof,comprising drawings and specication, and as will more fully appear,reference being had to the characters of reference used throughout thespecification and found upon like parts of the drawings, in which Fig. lshows a top plan view of my novel automatic electric reversing switch;

Fig. 2 is a longitudinal sectional View of the same, taken on line 2-2of Fig. l;

Fig. 3 shows a cross section taken on line 3-3 of Fig. 1;

Fig. 4 is an end View of a commercial type of rotary electric furnacehaving one of my electric switches mounted thereon and connected to beoperated thereby; and

Fig. 5 is a detailed view showing an assembly of rocker shaft 42, arm 40and collar 48 including its adjusting screw.

I will first refer to Fig. 4 of the drawings wherein is shown an endview of a modern type of rot/ary electric furnace to which my improvedswitch is shown applied. This furnace, as will be seen, includes a baseII, a cylindrical metal container I2 having a closable opening I3through which the furnace is charged and the melted metal is poured.

Four rollers I4, two of which are carried by each of the shafts I5 andI6 serve to rotatably support the cylindrical container I2 of thefurnace, the said cylinder being rocked through its frictionalengagements with the rollers on the s Claims. (ci. o- 47) shaft I5 thatin tarn are journaled in the base I I and connected to-be .driven by thereversible motor I'I connectedwith the far end of the shaft I5. Inaddition tothe two rollers mounted on the shaft I6, there is-alsoprovided thereon a sprocket 5 wheel I8 which is connected by a sprocketchain I9 with a sprocket wheel 26 on the feed screw 2| of my improvedelectric switch 22 that is shown supported on a bracket 23 secured tothe before mentioned base of the furnace. This switch is 10 connectedthrough a magnetic reversing switch, not shown, with the beforementioned motor I1 so as to properly eect its reverse drive with-theaction of the -switch of the invention.

My reversing switch 22 will be'mor'e readily 15 understood withreference to Figs. 1, -2 and 3,

Awhere it will be'seen that the same comprises a frame including a bed25 formed of cast metal and two upwardly extended bearing ribs 26, oneat eachend which serve in part to support the 20 before mentioned feedscrew 2| and an adjusting screw 21, the said feed screw being operatedthrough the sprocket and chain connections heretofore-referred to whilethe adjusting screw is provided with a handle 28 so as to facilitate an25 adjustment of parts of the switch.

A Vsuitable block of insulating material 29 is attached on each of theribs 26 by means of screws 38. These insulating blocks in turn arenotched as at 3| to receive current-carrying guide 3o bars 32, 33, 33a,34, 35 and 35B. The bars 32 and. 34 are full length bars, whereas thebars 33 and 33a, and 35 and 35a, connected by insulations 36, theportions 33 and 35 serving for the electric circuit breakers on support3l while the shorter 35 end portions are connected with the circuitbreakers on support 38.

Upon these bars are mounted two movable supports 31 and 38 which areformed of in sulating material and serve to carry electric-circuitclosers and openers. The insulative support 38 is movably mounted uponthe guide bars and is adapted for short longitudinal movements as insetting it and its contacting means when the switch is beinginstalled,`and to properly adapt its action to the required operation ofthe furnace or other machine, the operation of which it is4 to control.

From the foregoing it will be seen that my im` proved switch is operatedby the furnace, whose movements it controls through the sprocket andchain connections with the feed screw 2| journaled in the beforementioned ribs 26 of the bed. This feed screw carries a nut 39 backwardand forward with its forward and reverse rotations to alternately engagearms 40 and 4| to operate their rocker shafts 42 carrying electriccontacting means, as will later be described.

An adjusting screw 43 having its bearing 44 in the insulation block 29serves for the adjust- 60 ment of the support 38 with which said screwthreadably engages. A larger screw 21 which has itsbearings in the ribs25 threadably engages a metal block 45 secured to the underside of thesupport -31 and whereby the support is adjusted backward and forwardupon the bars 32, 33, 34 and 35 toward and from the before mentionedsupport 38, the said screw 21 being provided with a handle 28 by'meansof which it is turned for the purpose support 31.

In the beginning of the melting of a charge of metal, it is rstnecessary to turnthe screw 21 in a way to move the support 31inward-close to the insulation 36 and againstthe limit screw 43. Thisinsures, for the beginning, of the operation, the shorter rockingmovements of the furnace, whereas a further turning of the screw fromtime to time in the .opposite will delay the operation of themercuryswitches carried by the supports and consequently cause-longerrocking movements of the furnace. These latter adjustments are obviouslyaccomplished` during the operation of the furnace and are made from timeto time to increase the throw as theknetal becomes melted. Whlethe othersupport 38 is adjustable as by means of the before mentioned screw 43,yet this adjustment is'made only wliemthe switch 2,2 is installed toform afixedlimit of V,movementh1 of the furnace in one direction, suchfor instance ns would bring the opening I3 ofthe cylinder and its spoutin aposition for pouring.

` are secured to opposite' end Like bearings 4 1 portions'of -each'ofthe supports 31 and 38 to mount the rocker shafts '42 which carryupon their outer ends inwardly'and downwardly projecting arms 4|l and 4|that are'engaged by the before mentioned floating nut 39 mounted l.uponthe feed screw 2|. These arms are loosely mounted upon their shafts,being normally supported in the position shown in Figs. 2 and 5, bymeans of a collar 48 secured to the rocker shaft 42 and whereby theshaft will be rocked against the action of a spring 49 mounted on theshaft and having one end secured thereto and the other one secured tothe before mentioned bearing.

At this point it might be fitting to state that the two supports 31 and38 including their rocker shafts and electric contacting mechanismscarried by said shafts are substantially alike in both instances andtherefore like characters of reference will be applied to similar partsof the two sets. Upon each shaft 42 are pairs of arms 50-59 set atslightly different relative angular positions, and which are providedwith transparent tubular liquid-metal containers 5| having suitablecontacts 52 whereby when the rocker shafts and arms are in one positionan electric contact will be insured whereas when in another positionsaid contacts will be broken and others made. Suitable wire connectionsa, b, c and d are made from the mercury switch contacts to theconducting bars and these in turn having wire connections e, f, g, h andi with a commercial type of magnetic reversing switch, not shown.

From the foregoing description it will be understood that with the partsin the position shown in Fig. 1, a drive of the feed screw 2| as fromthe furnace will cause the nut 39 upon the feed screw to be fed forwardand engage with the arm 40 or 4| according to the direction of rotationof the feed screw. This engagement will cause the shaft 42 upon whichthe arm 4U or 4| 75 is mounted to be rocked" so that the arms 5|l'on ofadjusting the said said shaft would be swung over into a differentposition so that the liquid metal such as mercury, carried in thetransparent tubes mounted in the outer end portions of said arms, wouldbe shifted to reverse the respective'electric contacts of theswitches..` This change of contact is obviously conveyed through thewire connections, guide nut 39 with the arms 40 and 4| In thisconnection it will also be apparent that' t the nearer the support `31is positioned to the", support 38, the quicker the engagements of thea'qu'icker reversal or shorter rocking movement of the furnace. Thisre-positionng, or adjusting of the support 31 during the operation ofthe furnace, as before stated, is brought about by 'the operation of ahandle 28 and its shaft 21, 25 'from time to time,'during the melting ofthe charge of metal'ln the furnace.

.Having thus described my invention, whatl "claim and desire to secureby Letters Patent is: l

1. In an automatic revcrsime electric switch, i a frame, a reversiblefeed screw, electric conducting guide rods, switch-carrying supportsmountj 'ed'on the rods, separate means for adjusting one Asupport on therods with respect to the other, a

,rocker shaft carried on each support, arms upon fthe shafts, liquidmetal contacting means carried by the arms, means for holding the rockershafts n their normal positions, a floating nut mounted upon the feedscrew, acontact arm carried upon each rocker shaft and projected in theline of 0' travel of the saidnut for alternately operating the shafts.

2. In an automatic reversible electric switch, a frame, a feed screw,insulating blocks mounted on the frame, electric conducting guide rods45 mounted in the blocks, insulating supports mounted on the rods, meansfor adjusting either support on the rods with respect to the other, arocker shaft carried on each support, arms upon each shaft that areprojected at different angles, 50 'alternately operatable electricalcontacting means'carried by the arms, means for holding the rockershafts in their normal positions, a floating nut mounted upon the feedscrew, a contact arm carried upon each rocker shaft and projected in theline of travel of the said nut.

3. An automatic reversible electric switch, including a frame, areversible feed screw, insulating blocks mounted on the frame, electricoonducting guide rods mounted in the blocks, switch 30 carrying supportsadjustably mounted von the rods, a separate adjusting screw foradjusting one support on the rods with respect to the other while theswitch is in use, a rocker shaft carried on each support, a pair ofswitch arms upon each 65 shaft, electric contacting means carried byeach arm, yieldable means for holding the rocker shafts in their normalpositions, a oating nut mounted upon the feed screw, contact meanscarried upon each rocker shaft and projected in the 70 line of travel ofsaid nut for alternately operating the shafts and their electriccontacting means and electric wire connections from the contact means tothe guide rods.

OTTO KESSLER.

and consequently..

